Retractable blade knife



FIG. 1 is a side elevational view of the retractable blade knife showing my new design with the blade extended;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view of the retractable blade knife showing my new design with the blade in the retracted position;

FIG. 4 is a side elevational view thereof;

FIG. 5 is an opposite side elevational view thereof;

FIG. 6 is a front elevational view thereof;

FIG. 7 is a cross-sectional view thereof taken along the line 7--7 in FIG. 5;

FIG. 8 is a top plan view thereof;

FIG. 9 is a bottom plan view thereof. 

The ornamental design for a retractable blade knife, as shown and described. 